Our notification center 'Informant Today' widget is designed to be simple and useful.
With notification center widgets we have a very strict set of requirements to follow technically as far as size and memory usage and so we've designed the widget to allow weather, today's remaining events and tasks due today. Most of the other options we've been asked such as adding overdue tasks, and others would in general mean the widget would be too big to meet these requirements.
With iOS 14 we can now also offer a homescreen widget. This widget will have more options and sizes available to allow you a few more customization options.